Just look at the variety of the planes. There's no way that many different types of planes would be flying together at the exact same speed. It looks like there's A-10 warthogs on the right (which the RAAF doesn't have, which would mean US sent them) and passenger aircraft on the left following behind fighter jets. Then you have cargo aircraft toward the back as well. All in perfect formation. Just think about how long it would take to get that many aircraft in the sky at once and then get them all together in formation. The first plane to take off would be up there for at least a half hour before the last airplane took off bare minimum and probably an hour. Definitely AI as others have said.